Naphthalene derivatives



United States Patent Patented Oct. 10, 1961 "ice The present invention relates to naphthalene derivatives and the manufacture thereof.

It has. been found that naphthalene derivatives of the general Formula I possess valuable antimalarial activity againstthe' blood forms of Plasmodium species, being sevv eral times more active than quinine. The compounds have the additional advantages that they act rapidly, can be made simply and cheaply, and are almost tasteless.

In this formula one ofthe groups R andR and one of the groups R and R is'anhydroxy group; the other of the groupsR and R and of the groups R and R is a group represented by the formula --CH NHR in which R is-a straighter. branched alkyl 'group having from- 1 to 8 carbon atomsor a cycloalkyl group' having from 5 to 7 carbon atoms in the ring.

The compounds maybe presented as their therapeutically' acceptable acid-addition; salts.

They may be prepared byreacting the appropriate naphthalene-diol with formaldehyde and: the appropriate amine R NH in a. suitable solvent such as methanol; the reagents will react onstanding or may be heated together. The product of this reaction is a bis-oxazine compound. This oxazine compound is formed adjacent to each of the aphthalene rings by condensation of formaldehyde (which is present in excess during the reaction) uniting the R N and the oxygen. ortho to it as follows:

The oxazin'e rings can be opened and the formaldehyde removed in a manner to be described below.

As an examplethe'following sequence of formulae illustrates the'preparation of the compound 2:5-bis'(cyclo-' hexylaminomethyl)naphthalene-1:6 diol, which is the pre= rferred' compound;

Other valuable compounds may be prepared by starting from naphthalene-1 :S-diol or naphthalene-2:6-diol.- The opening of the oxazine rings in a compound of the type in Formula II may be carried out by treating with an acid in a suitable solvent such as aqueous propanol oi" aqueous isopropanol. For this purpose 10% hydrochloric? acid or 2- N sulphuric acid are convenient. The reaction may also be carried out in the cold in the presence of a; compound such as 2:4-dinitrophenylhydrazine which will react with forrnaldehyde as it is formed; this preventsloss of material due to polymerization; 'I t hasalso been found that compounds of thetype illus; trated by Formula. II possess an antimalarial activity sim ilar to that possessed by the compounds of Formula I This is probably due to their conversion in vivo to the latter.

The present invention in one aspect therefore comprises av base of the structure expressed by (1), its acid-addition saltsaudits condensation products with formaldehyde produced by replacingthe mobile hydrogens from R and R and also from R and R by, in each case, a cyclicbound. methylene group. I

The invention also comprises a method of preparing a compound of the type illustrated by Formula II wherein an appropriatenaphthalene-dbl is reacted with formaldehyde and-an amine R NH The invention also comprises the further step of treating a compound of the general type shown by Formula IL-with an acid, optionally in the presenceof acompound'fcapableof reacting with formaldehyde, to give a compound of Formula I.

The" invention will now be described with reference to the accompanying examples in which all temperatures are given in degrees centigrade.

' EXAMPLE 1 (a) 2:9-dicycl0hexyl-1:2:3:4:7:8:9:I 0-octahydro-2 :9- diaza'-4:7-dioxachrysene To a mixture of cyclohexylamine (22.8 cc.) and formalin (37 co.) in methanol cc.) kept at -'5' was added'a solution of naphthalene-1:6-diol' (16 g.) in methanol (150 cc.). After standing overnight, the deposited oily oxazine' was stirred with a mixture of ether and water and was filtered. It had a melting point of 130 after crystallization from either ethanol or dioxan.

(b) 2:5-bis(cyclohexylaminomethyl)naphthalene-1:6- dial dihydrochloride (a) 2:8-di'cyclbhexyl-1:2:3:4:7:8:9iI0-0ctahydro-2:8- diam-4:1 O-dioxachrysene This was prepared as described in Example 1(a) from naphthalene-lzS-diol, and crystallized from dioxan, melting point 183-184".

(b) 2:6 bis(cyclohexylaminomethyl)naphthalene 1:5-

diol hydrochloride The above oxazine base (4 g.) was dissolved in dry chloroform and alcoholic hydrochloric acid added dropwise.,, ffhe precipitated solid was washed with chloroform and obtained as a white solid, melting point 250 with. decomposition.

(a) 3:9 dicyclohexyl 1:2:3:4:7:8:9:I0 octahydro-3:9- diazo-kZ-dioxachrysene (b) 1:5 bis(cyclohexylaminomethyl)naphthalene 2:6- diol hydrochloride The oxazine base was hydrolyzed as Example 1(b), giving a white solid, melting point 266-268".

-The following compounds were prepared by methods similar to those employed in the above examples.

(A) From 1:S-dihydroxynaphthalene:

7 2(a) 2:8 di n-propyl-l :2:3:4:7:8:9:10octahydro- 2:8-diaza-4:lO-dioxachrysene, melting point 110- 115.

' 2(b) 2:6 bis(n propylaminomethyl)naphthalene- 1:5-diol dihydrochloride, melting point greater than 250 with decomposition.

(B) From 1:6-dihydroxynaphthalcne:

3(a) 2:9-diethyl-1:2:3:4:7:8:9:l0 octahydro-2t9- diaza-4z7-dioxachrysene, melting point greater than 230 with decomposition.

3(b) 2:5 bis(ethylaminomethyl)naphthalene 1:6-

diol dihydrochloride, melting point 197-199 with decomposition.

4(a) 2:9 di-n-propyl 1:2:3:4:7:8:9:10-octahydro- 2:9-diaza-4:7-dioxachrysene, as an oily solid.

4(b) 2:5 bis(n propylamin'omethyl)naphthalene- 1:6-diol dihydrochloride, melting point. l70172 with decomposition.

5(a) 2:9 n butyl 1:2:3:4:7:8:9:10-octahydro- 2:9-diaza-4:7-dioxachrysene, as an oily solid.

5 (b) 2:5 bis(n-butylaminomethyl)naphthalene-l:6-

diol dihydrochloride, melting point 180182 with decomposition. 1

6(a) 2:9 di n-octyl-l:2:3:4:7:8:9:10-octahydro- 2:9-diaza-4:7-dioxachrysene, as an oily solid.

6(b) 2:5 bis(n octylaminomethyl)naphthalene- 1:6-diol dihydrochloride, melting point'170-l75 with decomposition.

7(a) 2:9 dicyclopentyl 1:2:3:4:7:8:9:l0-octahydro-2:9-diaza-4:7 dioxachrysene, melting point 140-143 with decomposition.

7(b) 2:5 bis(cyclopentylaminomethyl)naphthalene-1z6-diol dihydrochloride, melting point 200- 205 with decomposition.

8(a) 2:9 dicycloheptyl 1:2:3:4:7:8:9:10-octahydro-2:9-diaza-4:7 dioxachrysene, melting point with decomposition.

8(b) 2:5 bis(cycloheptylaminomethyl)naphthalene-1:6-diol dihydrochloride, melting point 205- 206 with decomposition. From 2 6-dihydroxynaphthalene: 9(a) 3:9 dimethyl 1:2:3:4:7:8:9:lfl-octahydro- 3:9-diaza-1:7-dioxachrysene, melting point 198- 200 with decomposition.

9(b) 1:5 bis(methylaminomethyl)naphthalene- 226-diol dihydrochloride, melting point greater than 300 with decomposition.

- 10(a) 3:9 diethyl 1:2:3:4:7:8:9:IO-octahydro- 3:9-diaza-1:7-dioxachrysene, as an oily solid.

10(b) 1:5 bis(ethylaminomethyl)naphthalenc-Z:6-

diol dihydrochloride, melting point 238-240 with decomposition.

11(a) 3:9 di n-propyl-l:2:3:4:7:8:9:10-octahydro-3:9-diaza-1:7-dioxachrysene, as an oily solid.

11(b) 1:5 bis(n-propylaminomethyl)naphthalene- 2 6-diol dihydrochloride, melting point greater than 230 with decomposition.

12(a) 3:9 di isopropyl-l:2:3:4:7:8:9:10-octahydro-3z9-diaza-1:7-dioxachrysene, as an oily solid.

12(b) 1:5 bis(isopropylaminomethyl)naphthalene- 2z6-diol dihydrochloride, melting point greater than 240 with decomposition.

13(a) 3:9 di n-butyl-lz2z324z7z8z9:10-octahydro- 3:9-diaza-1:7-dioxachrysene, melting point 126- 128 with decomposition.

13(b) 1:5 bis(n butylaminomethyl)naphthalene- 2z6-diol dihydrochloride, melting point 230 with decomposition.

14(a) 3:9 di n-pentyl-l:2:3:4:7:8:9:10-octahydro-3:9-diaza-1:7 dioxachrysene, melting point 113-115 with decomposition.

14(b) 1:5 bis(n pentylaminomethyl)naphthalene- 2:6-diol dihydrochloride, melting point 237-240 with decomposition.

What I claim is: 1. A compound selected from the class consisting of a free base represented by the formula:

wherein one of the groups R and R is hydroxyl, R is hydroxyl and the other of the groups R and R and the group R are alkylaminomethyl groups of the structure R NHCH wherein R is a radical selected from the class consisting of the alkyl radicals having from three to six carbon atoms and the cycloalkyl radicals having from five'to seven carbon atoms and a therapeutically acceptable acid addition salt thereof.

2. A compound selected from the class consisting of.

5 6 2:5 bis(n-butylaminomethyl)naphthalene 1:6-di0l and 2,114,122 Bruson Apr. 12, 1938 a therapeutically acceptable acid addition salt thereof. 2,260,967 Bruson Oct. 28, 1941 5. A compound selected from the class consisting of ,441,57 Jone et 1 May18, 194 2:5 bis(n-propylaminomethyl) naphthalene 1:6-diol and a therapeutically acceptable acid addition salt thereof. 6 OTHER REFERENCES References Cited in the file of this patent 7 3 32 ggfg i gigf chemlcal Soclety UNITED STATES PATENTS Wiselogle: A Survey of Anti-Malarial Drugs (a bibli- 2,036,916 Bruson Apr. 7, 1936 0graphy),v0l-II,part p g 503 Z,045,517 Bruson June 23, 1936 10 Burke et al.: I. Am. Chem. Soc. 74, 602-5 (1952). 

1. A COMPOUND SELECTED FROM THE CLASS CONSISTING OF A FREE BASE REPRESENTED BY THE FORMULA: 